In a mobile communication system of the related art, in order to provide a better service to a subscriber group, it is generally required to form a plurality of radio resource management entities (i.e., a network entity which is used for managing radio resources and access of a user equipment (UE) in a radio access network, such as a base station or a cell in a variety of mobile communication systems) into a Closed Subscriber Group (CSG) for the specific subscriber group. For example, all subscribers within a company or a school are equal to a specific subscriber group, a plurality of radio resource management entities are formed into a CSG for this specific subscriber group to provide a special access service. It is widespread in a mobile communication system to form a plurality of radio resource management entities into a CSG for a specific subscriber group. In order to make this case clearer, a long term evolution (LTE) system of system architecture evolution (SAE) is taken as an example for explanation hereinafter.
FIG. 1 is a structure of the LTE system according to the related art.
Referring to FIG. 1, in a radio access network of the LTE system, a radio resource management entity includes a macro base station (e.g., evolved NodeB (eNB) 102) and a home eNodeB (HeNB) 103. A HeNB gateway (HeNB GW) 104 is optionally included in the radio access network. The eNB 102 may be directly connected with a mobile management entity (MME) 105 in a core network. When the HeNB GW 104 is included in the radio access network, the HeNB 103 is connected with the MME 105 through the HeNB GW 104. When the HeNB GW 104 is not included in the radio access network, the HeNB 103 may be directly connected with the MME 105.
For the radio resource management entity in the LTE system, in order to provide a richer access service, HeNBs of various types are provided in the related art, wherein the various types include an open type, a hybrid type and a CSG type. There is not a subscriber group of a specific access for an open HeNB, and any UE may access the open HeNB. A CSG HeNB is an HeNB that is used by the above described subscriber group consisting of all of the subscribers in the company or the school, the CSG HeNB only permits the access of a UE in the specific subscriber group which the CSG HeNB serves (for convenience of description, herein after a UE in a specific subscriber group is referred to as a CSG UE). A hybrid HeNB may form a CSG together with another HeNB, and permit the access of a CSG UE which the hybrid HeNB serves, at the same time, the hybrid HeNB may also permit the access of a non-CSG UE (i.e., a UE which does not belong to the CSG).
As can be seen from the above description, in the mobile communication system according to the related art, a plurality of radio resource management entities may be formed into a CSG to provide a CSG radio resource management entity, e.g., a CSG HeNB, and a hybrid radio resource management entity may be further provided to provide a richer access service, e.g., a hybrid HeNB. At the same time, the macro base station eNB may also support a function of the CSG, or may be used as a hybrid eNB when supporting the function of the CSG.
FIG. 2 is a schematic diagram illustrating an X2 setup process between eNBs according to the related art.
In the related art, for example, eNB1 detects a new neighbor cell, it is illustrated in FIG. 2 that eNB1 triggers an X2 setup process. It is easy to understand that descriptions of some processes which are optional and are well known to a person skilled in the art are omitted hereinafter. The X2 setup process may include operations as follows.
Referring to FIG. 2, at operation 201, eNB1 detects a new neighbor cell.
The eNB1 detects the new neighbor cell through a report of a UE, and the new neighbor cell is in eNB2.
At operation 202, eNB1 transmits to a MME an eNB configuration transfer message. The message contains an identifier of a source eNB, an identifier of a destination eNB, and self-optimization networks (SONs) information. The identifier of the source eNB is configured as a global eNB identifier of eNB1 and a selected tracking area identifier (TAI). The identifier of the destination eNB is configured as a global eNB identifier of eNB2 and the selected TAI. The SON information is configured as an information request which requests configuration information of an X2 Transport Network Layer.
At operation 203, the MME finds the destination eNB according to the identifier of the destination eNB (including the global eNB identifier and the selected TAI), and transmits to eNB2 a MME configuration transfer message.
At operation 204, eNB2 transmits to the MME the eNB configuration transfer message. The message contains the identifier of the source eNB, the identifier of the destination eNB, and the SON information. The identifier of the source eNB is configured as the global eNB identifier of eNB2 and the selected TAI. The identifier of the destination eNB is configured as the global eNB identifier of eNB1 and the selected TAI. The SON information includes SON information response which includes a Transport Network Layer (TNL) address of eNB2.
At operation 205, the MME transmits to eNB1 the MME configuration transfer message.
At operation 206, eNB1 transmits to eNB2 an X2 setup request message.
At operation 207, eNB2 transmits to eNB1 an X2 setup response message.
In a situation where there is a home base station, in order to reduce the on the core network, it is proposed to support an X2 handover between an eNB and the home base station. Considering that there are a larger number of home base stations within the coverage of the eNB, if the eNB sets up an X2 connection with each neighbor home base station, a great burden will be caused to the eNB, especially the burden of the transport network layer. In addition, the home base stations often start up and shutdown, which also brings a negative impact on the eNB, as a result, a concept of an X2 gateway (X2 GW) is proposed.
FIG. 3 is a schematic diagram illustrating a structure of a system including an X2 GW according to the related art.
Referring to FIG. 3, the HeNB is connected with the eNB through the X2 GW.
In this situation, the existing X2 setup process cannot complete an X2 setup process between the eNB and the X2 GW or an X2 setup process between the eNB and a peer HeNB through the X2 GW, and it is not resolved in the related art how to perform the X2 setup process. One method is to complete the setup through configuration of an operator, e.g., configuration of the eNB, the HeNB, the X2 GW, but this method brings a great burden to the operator.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.